I need to get the time that a Tor server or an IP address first appeared in the consensus.
Is it possible to use Stem to get this kind of information? If not, how do I get the time of a server or IP address first appearance using python?
The Tor metrics portal has historic information about consensuses. You could download the archive and search through them. You don't need Stem for that unless you want to verify the consensuses. I'd suggest just using grep instead of Python to check if a relay was in the consensus at a specific time.